Heat Pump

ABSTRACT

A subcooler is made up of a plate type heat exchanger. The accumulator is located between a compressor and the subcooler in a width direction of an outdoor unit in a planar view. The subcooler overlaps with the accumulator in the width direction in the planar view. As a result, a compact heat pump can be provided when the subcooler is a plate type heat exchanger.

TECHNICAL FIELD

The present invention relates to a heat pump and, for example, to anengine-driven heat pump using a gas engine etc. and anelectrically-driven heat pump.

BACKGROUND ART

Conventional refrigerating apparatuses include an apparatus described inJapanese Laid-Open Patent Publication No. 2002-310518 (Patent Document1). This refrigerating apparatus includes a compressor, a condenser, anevaporator, and a subcooler, and the subcooler is made up of a platetype heat exchanger, a shell-and-tube heat exchanger, etc. Thisrefrigerating apparatus is provided with the subcooler and is therebyincreased in heat exchange capacity and in refrigeration efficiency.

Patent Document

Patent Document 1: JP 2002-310518 A

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

The present inventor found the following problems in a heat pump havinga subcooler (the following description is not a conventional art andcannot be cited for denial of patentability of the present invention).

To increase a cooling performance during cooling, a plate type heatexchanger with a large heat exchange capacity and high coolingefficiency is adopted as a subcooler in some cases. Additionally, a heatpump may be provided with an accumulator for separating a gaseousrefrigerant and an atomized refrigerant.

However, in this case, since the volume of the accumulator is large andthe volume of the plate type heat exchanger is also large, the heat pumpincreases in size unless the accumulator and the plate type heatexchanger are properly arranged. However, a method of compactlyarranging the accumulator and the plate heat exchanger is not known.

If a receiver storing a liquid refrigerant is provided, a subcooler canbe disposed in the receiver if the subcooler is not a plate type heatexchanger. However, if a plate type heat exchanger having a large volumeis adopted as the subcooler, the subcooler cannot be disposed in thereceiver, and the heat pump must further have a receiver with a largevolume disposed in a space other than the space for arranging theaccumulator and the plate type heat exchanger. However, a method ofcompactly arranging the receiver, the accumulator, and the plate typeheat exchangers is not known.

If an oil separator separating a lubricating oil of a compressor from arefrigerant gas is provided, a space for disposing the oil separatorhaving a large volume is required. However, a method of compactlyarranging the receiver, the accumulator, the oil separator, and theplate heat exchanger is not known.

Therefore, a problem to be solved by the present invention is to providea compact heat pump when the subcooler is a plate type heat exchanger.

Means for Solving Problem

To solve the problem, a heat pump according to an aspect of the presentinvention is a heat pump having an outdoor unit which houses a receiver,an accumulator, an oil separator, and a subcooler in a package, in theoutdoor unit, the subcooler provided in a liquid refrigerant path of arefrigerant flow downstream of the receiver, the accumulator provided inan intake path of a compressor, and the oil separator provided in adischarge path of the compressor, wherein

the subcooler is a plate type heat exchanger, and

two members of the receiver, the accumulator, the oil separator, and thesubcooler are arranged on a straight line inclined to one side in awidth direction of the outdoor unit with respect to a depth direction ofthe outdoor unit in a planar view, and

the remaining two members of the receiver, the accumulator, the oilseparator, and the subcooler are arranged on a straight line inclined tothe other side in the width direction of the outdoor unit with respectto the depth direction of the outdoor unit in the planar view, and

each of the two members on the straight line inclined to the one side isadjacent to each of the remaining two members in the planar view.

A heat pump according to another aspect of the present invention is aheat pump comprising an outdoor unit housing in a package a subcoolerprovided in a refrigerant flow downstream of a receiver and anaccumulator provided in an intake path of a compressor, wherein

the subcooler is a plate type heat exchanger, and

the accumulator is located between the compressor and the subcooler in awidth direction of the outdoor unit in a planar view, and

the subcooler overlaps with the accumulator in the width direction ofthe outdoor unit in the planar view.

Effect of the Invention

According to the present invention, a compact heat pump can be achievedwhen the subcooler is a plate type heat exchanger.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a simplified refrigerant circuit diagram of agas-engine-driven heat pump according to an embodiment of the presentinvention.

FIG. 2 is a perspective view of an outdoor unit with a package removedand is a perspective view of a portion of an internal structure of theoutdoor unit.

FIG. 3 is a perspective view of a portion of the outdoor unit with thepackage removed when viewed from a gas engine mounting side.

FIG. 4 is a plane view of the outdoor unit with the package removed andis a view of a receiver, an accumulator, an oil separator, and asubcooler viewed from directly above (the upper side) in the outdoorunit with the package removed.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

A heat pump according to an aspect of the present invention is a heatpump having an outdoor unit which houses a receiver, an accumulator, anoil separator, and a subcooler in a package, in the outdoor unit, thesubcooler provided in a liquid refrigerant path of a refrigerant flowdownstream of the receiver, the accumulator provided in an intake pathof a compressor, and the oil separator provided in a discharge path ofthe compressor, wherein the subcooler is a plate type heat exchanger,and two members of the receiver, the accumulator, the oil separator, andthe subcooler are arranged on a straight line inclined to one side in awidth direction of the outdoor unit with respect to a depth direction ofthe outdoor unit in a planar view, and the remaining two members of thereceiver, the accumulator, the oil separator, and the subcooler arearranged on a straight line inclined to the other side in the widthdirection of the outdoor unit with respect to the depth direction of theoutdoor unit in the planar view, and each of the two members on thestraight line inclined to the one side is adjacent to each of theremaining two members in the planar view.

The planar view is defined as a field of view (range of view) when thereceiver, the accumulator, the oil separator, and the subcooler areviewed from directly above (the upper side) while the outdoor unit ofthe heat pump is placed on the horizontal plane in a posture in a usagestate.

The requirement of arrangement on the straight line is satisfied as longas any portion of a member overlaps with the straight line in the planarview.

Hereinafter, when a wording (expression) related to height such as ahorizontal direction, a vertical direction, and a height direction isused in this description, the wording refers to a direction etc. in thestate of the outdoor unit placed on the horizontal plane in a posture ina usage state.

According to an embodiment of the present invention, the four membershaving large volumes can densely be arranged in a rectangular space inthe planar view. Therefore, the compact outdoor unit can be achieved. Byarranging the plate type heat exchanger in a gap when the receiver, theaccumulator, and the oil separator are provided, the space canefficiently be utilized.

A heat pump according to another aspect of the present invention is aheat pump comprising an outdoor unit housing in a package a subcoolerprovided in a refrigerant flow downstream of a receiver and anaccumulator provided in an intake path of a compressor, wherein thesubcooler is a plate type heat exchanger, and the accumulator is locatedbetween the compressor and the subcooler in a width direction of theoutdoor unit in a planar view, and the subcooler overlaps with theaccumulator in the width direction of the outdoor unit in the planarview.

In this description, overlapping in the width direction meansoverlapping when viewed in the width direction, and overlapping in thedepth direction means overlapping when viewed in the depth direction.

The planar view is defined as a field of view (range of view) when theaccumulator and the subcooler are viewed from directly above (the upperside) while the outdoor unit of the heat pump is placed on thehorizontal plane in a posture in a usage state. The width direction isdefined as the direction in which a power source of the outdoor unitsuch as a gas engine is disposed adjacent to the outdoor unit.

According to the other aspect of the present invention, the subcooler isdisposed on the side opposite to the compressor with respect to theaccumulator in the width direction so as to overlap with the accumulatorin the width direction in the planar view. Therefore, the space tendingto be a dead space can effectively be utilized on the side opposite tothe compressor in the width direction with respect to the accumulatorwith a large volume. Thus, even though a plate type heat exchanger witha large volume is adopted as the subcooler, the compact outdoor unit canbe achieved.

The present invention will now be described in detail with a shownembodiment.

FIG. 1 is a simplified refrigerant circuit diagram of agas-engine-driven heat pump according to an embodiment of the presentinvention.

As shown in FIG. 1, this heat pump includes an outdoor unit 50, anindoor unit 100, a gas refrigerant pipe 110, and a liquid refrigerantpipe 120. This heat pump also includes a controller 60 for the outdoorunit 50. A dotted line denoted by 80 of FIG. 1 indicates a package ofthe outdoor unit 50. As shown in FIG. 1, the gas refrigerant pipe 110and the liquid refrigerant pipe 120 each connect the outdoor unit 50 andthe indoor unit 100.

The outdoor unit 50 includes a first compressor 1, a second compressor2, an oil separator 3, a four-way valve 4, a gas-side stop valve 5, agas-side filter 6, a liquid-side filter 9, a liquid-side stop valve 10,a first check valve 11, a second check valve 12, a third check valve 13,a fourth check valve 14, a receiver 17, and a subcooler 18. The outdoorunit 50 also includes a first electronic expansion valve 20, a secondelectronic expansion valve 21, a first outdoor heat exchanger 23, asecond outdoor heat exchanger 24, an accumulator 26, a sub-evaporator(refrigerant auxiliary evaporator) 27, a third electronic expansionvalve 35, a fourth electronic expansion valve 36, an electromagneticvalve 38, and a fifth check valve 39. On the other hand, the indoor unit100 has an indoor heat exchanger 8.

The controller 60 outputs control signals to the first compressor 1, thesecond compressor 2, the four-way valve 4, the first electronicexpansion valve 20, the second electronic expansion valve 21, the thirdelectronic expansion valve 35, the fourth electronic expansion valve 36,and the electromagnetic valve 38 to control these devices. Although notshown, the controller 60 is electrically connected through a signal lineto each of these devices.

As shown in FIG. 1, the first compressor 1, the second compressor 2, thegas-side stop valve 5, the liquid-side stop valve 10, the gas-sidefilter 6, and the liquid-side filter 9 are provided in the package 80 ofthe outdoor unit 50. The receiver 17, the accumulator 26, the oilseparator 3, and the subcooler 18 are also provided in the package 80 ofthe outdoor unit 50.

The first compressor 1, the second compressor 2, the gas-side stop valve5, the liquid-side stop valve 10, the gas-side filter 6, and theliquid-side filter 9 are arranged in the same chamber defined by thepackage 80. The receiver 17, the accumulator 26, the oil separator 3,and the subcooler 18 are also arranged in the same chamber describedabove. The package 80 is a case made up of a plurality of outer plates,for example.

As shown in FIG. 1, the first compressor 1 and the second compressor 2are arranged in parallel, and lines on the discharge side of the firstand second compressors 1, 2 are connected to a refrigerant inlet of theoil separator 3. The oil separator 3 is provided in a discharge path ofthe compressors 1, 2. The refrigerant outflow side of the oil separator3 is connected to a first port 30 of the four-way valve 4. A second port31 of the four-way valve 4 is connected via the gas-side stop valve 5and gas-side filter 6 to a port on the gas side of the indoor heatexchanger 8. The gas-side filter 6 is disposed on the indoor unit 100side relative to the gas-side stop valve 5 and inside the package 80 ofthe outdoor unit 50.

A port on the liquid side of the indoor heat exchanger 8 is connectedthrough the liquid-side filter 9 and the liquid-side stop valve 10 to aline 25 connecting a port on the refrigerant outflow side of the firstcheck valve 11 and a port on the refrigerant inflow side of the secondcheck valve 12. The liquid-side filter 9 is disposed on the indoor unit100 side relative to the liquid-side stop valve 10 and inside thepackage 80 of the outdoor unit 50. A port on the refrigerant outflowside of the first check valve 11 is connected through a line 55 to aport on the refrigerant inflow side of the receiver 17. A port on therefrigerant outflow side of the receiver 17 is connected through thesubcooler 18 to respective ports on the refrigerant inflow side of thesecond and fourth check valves 12, 14. The subcooler 18 is provided in aliquid refrigerant path of a refrigerant flow downstream of the receiver17.

As shown in FIG. 1, a port on the refrigerant outflow side of the fourthcheck valve 14 and a port on the refrigerant inflow side of the thirdcheck valve 13 are connected by a line 56. The first and secondelectronic expansion valves 20, 21 are connected in parallel to a line57 branched from the line 56. The first and second outdoor heatexchangers 23, 24 are connected in parallel to a line 58 led out from aside of the first and second electronic expansion valves 20, 21different from the side connected to the check valves 13, 14. The firstand second electronic expansion valves 20, 21 are connected in series tothe first and second outdoor heat exchangers 23, 24.

A line 59 led out from a side of the first and second outdoor heatexchangers 23, 24 different from the side connected to the electronicexpansion valves 20, 21 is connected to a third port 32 of the four-wayvalve 4. As shown in FIG. 1, a fourth port 33 of the four-way valve 4 isconnected to the accumulator 26. The accumulator 26 is connected to theintake side of the compressors 1, 2. The accumulator 26 is provided inan intake path of the compressors 1, 2.

The port on the refrigerant inflow side of the fourth check valve 14 isconnected via the third electronic expansion valve 35 to thesub-evaporator 27. A side of the sub-evaporator different from the sideconnected to the fourth check valve 14 is connected to a line 61connecting the fourth port 33 of the four-way valve and the accumulator26.

A new line 63 is branched from the line 62 connecting the port on therefrigerant inflow side of the fourth check valve 14 and the thirdelectronic expansion valve 35. The branched line 63 is connected throughthe fourth electronic expansion valve 36 to the subcooler 18. As shownin FIG. 1, the subcooler 18 is directly connected through a line 41 to aline 40 connecting the accumulator 26 and the compressors 1, 2. Therefrigerant passing through the subcooler 18 passes through thesubcooler 18 and then flows through the line 41 toward the compressors1, 2.

As shown in FIG. 1, the line 58 connecting the outdoor heat exchangers23, 24 and the electronic expansion valves 20, 21 is branched, and aline 53 branched from the line 58 is connected to the line 55 connectingthe first and third check valves 11, 13 to the receiver 17. Theelectromagnetic valve 38 and the fifth check valve 39 are arranged onthe path of the branched line 53. As shown in FIG. 1, theelectromagnetic valve 38 is located closer than the fifth check valve 39to the outdoor heat exchangers 23, 24 on the line 53. The controller 60controls the electromagnetic valve 38 to a fully-opened or fully-closedstate.

In the configuration described above, this heat pump performs coolingand heating operations as follows.

First, in the heating operation, the controller 60 controls the four-wayvalve 4 to connect the first port 30 and the second port 31 of thefour-way valve 4 and connect the third port 32 and the fourth port 33.

In the heating operation, the high pressure refrigerant gas dischargedfrom the compressors 1 and 2 first flows into the oil separator 3. Theoil separator 3 separates a lubricating oil of the compressors 1, 2 fromthe refrigerant gas. Although not described in detail, the lubricatingoil separated from the refrigerant gas by the oil separator 3 isreturned to the compressors 1, 2 through a line not shown.

After passing through the oil separator 3, the refrigerant gas passesthrough the four-way valve 4, the gas-side stop valve 5, and thegas-side filter 6 in this order and flows into the indoor heat exchanger8. The gas-side stop valve 5 is a valve manually opened and closed (byusing a tool in some cases). The gas-side stop valve 5 is closed mainlywhen the outdoor unit 50 is connected to the indoor unit 100 at the timeof installation. The gas-side stop valve 5 plays a role of preventing aforeign matter from the outside from entering the outdoor unit 50 at thetime of installation. The gas-side filter 6 plays a role of removing aforeign matter from the outside at the time of installation. Thegas-side filter 6 is provided for protecting the outdoor unit 50.

The gas refrigerant gives heat to the indoor heat exchanger 8 andthereby liquefies itself into a liquid refrigerant. Subsequently, theliquid refrigerant flows via the liquid-side filter 9, the liquid-sidestop valve 10, and the first check valve 11 in this order into thereceiver 17. The liquid-side stop valve 10 is a valve manually openedand closed (by using a tool in some cases). The liquid-side stop valve10 is closed mainly when the outdoor unit 50 is connected to the indoorunit 100 at the time of installation. The liquid-side stop valve 10plays a role of preventing a foreign matter from the outside fromentering the outdoor unit 50 at the time of installation. Theliquid-side filter 9 plays a role of removing a foreign matter from theoutside at the time of installation. The liquid-side filter 9 isprovided for protecting the outdoor unit 50.

The receiver 17 plays a role of storing the liquid refrigerant.Subsequently, the liquid refrigerant goes through the bottom of thereceiver 17, passes through the subcooler 18, runs through the fourthcheck valve 14, and flows toward the first and second electronicexpansion valves 20, 21.

The pressure of the liquid refrigerant coming out from the bottom of thereceiver 17 becomes lower due to a pressure loss through a path than thepressure of the liquid refrigerant on the outflow side of the secondcheck valve 12 and the pressure of the liquid refrigerant on the outflowside of the first and third check valves 11, 13. As a result, basically,the liquid refrigerant going through the bottom of the receiver 17 doesnot pass through the second check valve 12 and the third check valve 13.

Subsequently, the liquid refrigerant is expanded by the first and secondelectronic expansion valves 20, 21 and is sprayed and atomized. Theopening degrees of the first and second electronic expansion valves 20,21 are freely controlled by the controller 60. The pressure of therefrigerant is high before passing through the first and secondelectronic expansion valves 20, 21 and becomes low after passing throughthe first and second electronic expansion valves 20, 21.

Subsequently, the atomized damp liquid refrigerant exchanges heat withoutside air through the first and second outdoor heat exchangers 23, 24and gasifies due to the heat given from the outside air. In this way,while the refrigerant imparts heat to the indoor heat exchanger 8, heatis imparted from the outdoor heat exchangers 23, 24. Subsequently, thegasified refrigerant passes through the four-way valve 4 and reaches theaccumulator 26. The accumulator 26 separates the gaseous refrigerant andthe atomized refrigerant and fully gasifies the refrigerant. If therefrigerant remaining in the atomized state returns to the compressors1, 2, sliding parts of the compressors 1, 2 may be damaged. Theaccumulator 26 also plays a role of preventing such a situation.Subsequently, the refrigerant gas passing through the accumulator 26flows into intake ports of the compressors 1, 2.

If the third electronic expansion valve 35 is partially or completelyopened under the control of the controller 60, a portion of the liquidrefrigerant passing through the subcooler 18 is atomized by the thirdelectronic expansion valve 35 before flowing into the sub-evaporator 27.To the sub-evaporator 27, warm cooling water (cooling water at 60° C. to90° C.) of the gas engine is introduced.

The atomized liquid refrigerant flowing into the sub-evaporator 27indirectly exchanges heat with the warm cooling water and becomes a gasbefore reaching the accumulator 26. In this way, the performance ofgiving and receiving heat is improved. It is noted the when the heatingoperation is performed, the fourth electronic expansion valve 36 iscontrolled to be fully closed.

On the other hand, in the cooling operation, the controller 60 controlsthe four-way valve 4 to connect the first port 30 and the third port 32of the four-way valve 4 and connect the second port 31 and the fourthport 33. A flow of heat in the case of cooling will hereinafter simplybe described.

In the case of the cooling operation, the gas refrigerant dischargedfrom the first and second compressors 1, 2 passes through the oilseparator 3; then passes through the four-way valve 4, and reaches thefirst and second outdoor heat exchangers 23, 24. In this case, since thetemperature of the refrigerant is high, the refrigerant is cooled evenwith an intensely hot summer air (air at 30 to 40 degrees C.) by thefirst and second outdoor heat exchangers 23, 24. The gas refrigerant isdeprived of heat by the first and second outdoor heat exchangers 23, 24,turning into a liquid refrigerant.

During the cooling operation, the controller 60 controls the openingdegrees of the first and second electronic expansion valves 20, 21 to anappropriate opening degree and controls the electromagnetic valve 38 tobe fully opened. The liquid refrigerant passing through the first andsecond outdoor heat exchangers 23, 24 basically passes through theelectromagnetic valve 38 and the check valve 39 and reaches the receiver17. Subsequently, the liquid refrigerant goes through the bottom of thereceiver 17, passes through the subcooler 18, and flows from between thesecond check valve 12 and the first check valve 11 toward theliquid-side stop valve 10.

Subsequently, the liquid refrigerant flows via the liquid-side stopvalve 10 and the liquid-side filter 9 into the indoor heat exchanger 8.The low temperature liquid refrigerant flowing into the indoor heatexchanger 8 draws heat from the indoor heat exchanger 8 to cool a roomair while gasifying due to the heat given from the indoor heat exchanger8. In this way, the refrigerant draws heat from the indoor heatexchanger 8 while releasing heat to the first and second outdoor heatexchangers 23, 24. Subsequently, the gasified gas refrigerant passesthrough the gas-side filter 6, the gas-side stop valve 5, the four-wayvalve 4, and the accumulator 26 in this order and flows into the intakeports of the compressors 1, 2.

When the controller 60 receives a signal from a remote control operationby a user via a controller (not shown) and a signal line (not shown) ofthe indoor unit 100 in hot summer season etc., the controller 60controls the opening degree of the fourth electronic expansion valve 36to an appropriate opening degree. As a result, a portion of the liquidrefrigerant passing through the receiver 17 and the subcooler 18 iscooled by passing through the fourth electronic expansion valve 36 andflows into the subcooler 18. In this way, heat is exchanged between theliquid refrigerant flowing from the receiver 17 into the subcooler 18without passing through the fourth electronic expansion valve 36 and theliquid refrigerant passing through the fourth electronic expansion valve36 and flowing into the subcooler 18. As a result, while the liquidrefrigerant sent to the indoor heat exchanger 8 is further cooled, theliquid refrigerant passing through the fourth electronic expansion valve36 is warmed and gasified before being allowed to flow toward thecompressors 1, 2. The subcooler 18 is a plate type heat exchanger. Thisheat pump is improved in cooling performance by adopting a plate typeheat exchanger with a large heat exchange capacity as the subcooler 18.

FIG. 2 is a perspective view of an outdoor unit 50 with the package 80removed and is a perspective view of a portion of an internal structureof the outdoor unit 50.

In this perspective view, the oil separator 3, the receiver 17, and thefour-way valve 4 are located on the far side of the plane of FIG. 2,while the sub-evaporator 27, the accumulator 26, the one compressor 1 ofthe two compressors, the liquid-side stop valve 10, the liquid-sidefilter 9, the gas-side stop valve 5; and the gas-side filter 6 arelocated on the near side of the plane of FIG. 2.

In FIG. 2, reference numeral 81 denotes an oval flange (oval flange) forconnecting the line from the four-way valve 4 to the outdoor heatexchangers 1, 2 (not shown in FIG. 2) disposed on a second floor, andreference numeral 82 denotes an oval flange for connecting the linesfrom the outdoor heat exchangers 1, 2 to the receiver 17 side. The gasengine (not shown) is disposed on one side in the width direction of theoutdoor unit 50 indicated by an arrow A of FIG. 2 relative to theaccumulator 26 (the width direction mentioned in the followingdescription refers to the width direction of the outdoor unit 50).

FIG. 3 is a perspective view of a portion of the outdoor unit 50 withthe package 80 removed when viewed from a gas engine mounting side.

In FIG. 3, reference numeral 83 denotes a flywheel of the gas engine;reference numeral 84 denotes an electromagnetic clutch connecting anddiscontenting a power to the first compressor 1; reference numeral 85denotes a winding belt; and reference numeral 86 denotes anelectromagnetic clutch connecting and discontenting a power to thesecond compressor 2. As shown in FIG. 3, the winding belt 85 is woundaround the flywheel 83, the electromagnetic clutch 84, and theelectromagnetic clutch 86. The rotating power of the gas engine istransmitted through the flywheel 83 and the winding belt 85 to theelectromagnetic clutches 84, 86 and the rotating power is transmittedfrom the electromagnetic clutches 84, 86 to the compressors 1, 2.

FIG. 4 is a plane view of the outdoor unit 50 with the package 80removed and is a view of the receiver 17, the accumulator 26, the oilseparator 3, and the subcooler 18 viewed from directly above (upperside) in the outdoor unit 50 with the package 80 removed.

In FIG. 4, 1 denotes the first compressor, 2 denotes the secondcompressor, and 26 denotes the accumulator. In FIG. 4, 3 denotes the oilseparator, 17 denotes the receiver, and 18 denotes the subcooler (theplate type heat exchanger). An arrow A indicates the width direction,and an arrow B indicates the depth direction of the outdoor unit 50 (thedepth direction mentioned in the following description refers to thedepth direction of the outdoor unit 50).

As shown in FIG. 4, in a planar view, the oil separator 3 and thesubcooler 18 are located on a straight line P1 inclined to one side inthe width direction with respect to the depth direction. In the planarview, the straight line P1 is inclined by θ1[°] (θ1<90[° ]) to one sidein the width direction.

Additionally, in the planar view, the accumulator 26 and the receiver 17are located on a straight line P2 inclined to the other side in thewidth direction with respect to the depth direction. In the planar view,the straight line P2 is inclined by θ2[°] (θ2<90[° ]) to the other sidein the width direction. In the planar view, each of the oil separator 3and the subcooler 18 on the straight line P1 is disposed adjacent toeach of the accumulator 26 and the receiver 17. In the planar view, thestraight line P1 intersects with the straight line P2 between theaccumulator 26 and the receiver 17.

In the planar view, with regard to the subcooler 18, the accumulator 26is located between the subcooler 18 and the compressors 1, 2 in thewidth direction. In the planar view, the subcooler 18 overlaps with theaccumulator 26 in the width direction.

In the planar view, the accumulator 26, the oil separator 3, and thereceiver 17 each have a circular shape, and the subcooler 18 has arectangular shape. In the planar view, the area occupied by theaccumulator 26 is larger than the area occupied by the receiver 17 andlarger than the area occupied by the oil separator 3. In planar view,the area occupied by the accumulator 26 is larger than the area occupiedby the subcooler 18.

In the planar view, the area occupied by the receiver 17 issubstantially equal to the area occupied by the oil separator 3. In theplanar view, the area occupied by the subcooler 18 is smaller than thearea occupied by the receiver 17 and smaller than the area occupied bythe oil separator 3.

In the planar view, the oil separator 3 has a portion overlapping withthe accumulator 26 in the depth direction, and the subcooler 18 has aportion overlapping with the receiver 17 in the depth direction. In theplanar view, the receiver 17 has a portion overlapping with the oilseparator 3 in the width direction.

In the planar view, the accumulator 26 and the oil separator 3 face thecompressors 1, 2 in the width direction. In the planar view, thereceiver 17 and the subcooler 18 are located on the side opposite to thecompressors 1, 2 with respect to the accumulator 26 and the oilseparator 3 in the width direction. In the planar view, the straightline connecting the center of the circular oil separator 3 and thecenter of the circular receiver 17 is substantially parallel to thewidth direction.

In the planar view, the accumulator 26, the oil separator 3, and thereceiver 17 are arranged to draw an L shape. In the planar view, thesubcooler 18 is arranged in the space partitioned by the L shape.

According to the embodiment, since the subcooler 18 is a plate-type heatexchanger, the heat exchange capacity can be increased and the coolingperformance can be made excellent.

According to the above embodiment, the receiver 17, the accumulator 26,the oil separator 3, and the subcooler 18 having large volumes candensely be arranged in a rectangular region in the planar view.Therefore, the compact outdoor unit can be achieved. By arranging thesubcooler 18 in a gap when the receiver 17, the accumulator 26, and theoil separator 3 are provided, the space can efficiently be utilized.

According to the embodiment, the subcooler 18 is disposed on the sideopposite to the compressors 1, 2 with respect to the accumulator 26 inthe width direction so as to overlap with the accumulator 26 in thewidth direction of the outdoor unit 50 in the planar view. Therefore,the space tending to be a dead space can effectively be utilized on theside opposite to the compressors in the width direction with respect tothe accumulator 26 with a large volume. Thus, even though a plate typeheat exchanger with a large volume is adopted as the subcooler 18, thecompact outdoor unit 50 can be achieved.

By adjacently arranging the accumulator 26 having the largest size andthe subcooler 18 having the smallest size in the width direction in theplanar view and adjacently arranging the two members intermediate insize, i.e., the receiver 17 and the accumulator 26, in the widthdirection, the receiver 17, the accumulator 26, the oil separator 3, andthe subcooler 18 can densely be arranged in the rectangular region.

In the present invention, the receiver, the accumulator, the oilseparator, and the subcooler may be arranged in two rows and two columnsin a rectangular space in the planar view, and the receiver, theaccumulator, the oil separator, and the subcooler may each be disposedat any position in regions around the four corners of the rectangularregion in the planar view. For example, in the arrangement of theembodiment shown in FIG. 4, the arrangement positions of the oilseparator and the receiver may be interchanged. The arrangement of thereceiver, the accumulator, the oil separator, and the subcooler may beany pattern of arrangement out of possible 4! (the factorial of 4)=24combinations, and the embodiment is shown as merely one of the 24patterns of arrangement. Out of the 24 patterns of arrangement, thepatterns of arrangement with the accumulator and the subcooleroverlapping with each other in the width direction or in the depthdirection are preferable because a large member and a small member areadjacent to each other in the planar view so that a small arrangementspace can be achieved. Out of the 24 patterns of arrangement, the fourpatterns of arrangement with the accumulator and the oil separatordisposed on the side closer to the compressors (two combinations fordisposing the accumulator and the oil separator on the side closer tothe compressors and two patterns of arrangement of the receiver and thesubcooler for each of the two combinations, i.e., 2×2=4 patterns) arepreferable since the length of piping can be made short.

In any combinations, when two members of the receiver, the accumulator,the oil separator, and the subcooler are located on one straight lineand the remaining two members of the receiver, the accumulator, the oilseparator, and the subcooler are located on the other straight line inthe planar view, the presence of the one and the other straight linessatisfying the condition of intersecting between the other two membersis preferable because the four members can more densely be arranged.

In the embodiment, the straight line connecting the center of thecircular oil separator 3 and the center of the circular receiver 17 issubstantially parallel to the width direction in the planar view.However, in the present invention, the straight line connecting thecenter of the circular oil separator and the center of the circularreceiver may neither be parallel to the depth direction nor parallel tothe width direction in the planar view.

In the embodiment, the accumulator 26, the oil separator 3, and thereceiver 17 each have a circular shape in the planar view, and thesuperheat heat exchanger 18 has a rectangular shape. However, in thepresent invention, one or more members of the accumulator, the oilseparator, and the receiver may have a shape other than a circle in theplanar view and may have a shape such as a polygon and an ellipse, forexample. The superheat heat exchanger may have a shape other than arectangle in the planar view and may have, for example, a polygonalshape other than a rectangle.

In the embodiment, the heat pump has the one outdoor unit 50 and the oneindoor unit 100; however, in the present invention, the heat pump mayhave any number of one or more outdoor units and may have any number ofone or more indoor units.

In the embodiment, the heat pump is a gas-engine-driven heat pump;however, the heat pump of the present invention may be a heat pumpdriven by an engine other than a gas engine, such as a diesel engine anda gasoline engine. The heat pump of the present invention may be anelectrically-driven heat pump.

In the present invention, in comparison with the embodiment, one or moreelectrical components and parts can appropriately be omitted from theelectrical components and parts constituting the embodiment. On thecontrary, in the present invention, in comparison with the embodiment, afurther electrical component or part can be added to the electricalcomponents and parts constituting the embodiment.

In the present invention, a compressor power source such as an engineand an electric motor may be separated from a compressor by a sill so asto prevent the hot heat of the compressor power source from going to therefrigerant side, or a compressor power source such as an engine and anelectric motor may not be separated from a compressor by a sill.Additionally, a new embodiment can obviously be constructed by combiningtwo or more constituent elements out of all the constituent elementsdescribed in the embodiment and modification examples.

Although the present invention has been sufficiently described in termsof the preferable embodiment with reference to the accompanyingdrawings, various variations and modifications are apparent to thoseskilled in the art. It should be understood that such variations andmodifications are included in the present invention without departingfrom the scope of the present invention according to appended claims.

The disclosures of description, drawings, and claims of Japanese PatentApplication No. 2014-237143 filed on Nov. 21, 2014 are incorporatedherein by reference in their entirety.

EXPLANATIONS OF REFERENCE OR NUMBERS

-   1 first compressor-   2 second compressor-   3 oil separator-   4 four-way valve-   6 gas-side filter-   8 indoor heat exchanger-   9 liquid-side filter-   10 liquid-side stop valve-   17 receiver-   18 subcooler-   20 first electronic expansion valve-   21 second electronic expansion valve-   23 first outdoor heat exchanger-   24 second outdoor heat exchanger-   26 accumulator-   27 sub-evaporator-   35 third electronic expansion valve-   36 fourth electronic expansion valve-   38 electromagnetic valve-   50 outdoor unit-   60 controller-   80 package-   100 indoor unit-   110 gas refrigerant pipe-   120 liquid refrigerant pipe

1. A heat pump comprising an outdoor unit which houses a receiver, anaccumulator, an oil separator, and a subcooler in a package, in theoutdoor unit, the subcooler provided in a liquid refrigerant path of arefrigerant flow downstream of the receiver, the accumulator provided inan intake path of a compressor, and the oil separator provided in adischarge path of the compressor, wherein the subcooler is a plate typeheat exchanger, and two members of the receiver, the accumulator, theoil separator, and the subcooler are arranged on a straight lineinclined to one side in a width direction of the outdoor unit withrespect to a depth direction of the outdoor unit in a planar view, andthe remaining two members of the receiver, the accumulator, the oilseparator, and the subcooler are arranged on a straight line inclined tothe other side in the width direction of the outdoor unit with respectto the depth direction of the outdoor unit in the planar view, and eachof the two members on the straight line inclined to the one side isadjacent to each of the remaining two members in the planar view.
 2. Aheat pump comprising: an outdoor unit housing in a package a subcoolerprovided in a refrigerant flow downstream of a receiver and anaccumulator provided in an intake path of a compressor, wherein thesubcooler is a plate type heat exchanger, and the accumulator is locatedbetween the compressor and the subcooler in a width direction of theoutdoor unit in a planar view, and the subcooler overlaps with theaccumulator in the width direction of the outdoor unit in the planarview.